In general, there is known an electrostatic coating machine of a rotary atomizing head type as an electrostatic coating machine. The electrostatic coating machine includes an air motor having an electric potential which is maintained at a ground level and that rotates a rotational shaft with compressed air supplied thereto, a rotary atomizing head that is provided on the front side of the rotational shaft and is composed of a tubular body having an electric potential which is maintained at the ground level to spray paint, which is supplied while being rotated by the air motor, from a releasing edge in a front end, an external electrode member that is positioned in back of the rotary atomizing head to be provided on an outer peripheral side of the air motor and electrifies paint particles sprayed from the releasing edge in the rotary atomizing head to be in a negative potential by applying a negative high voltage to a plural numbers of electrodes, and a shaping air spurting member that is formed in a tubular shape by using a conductive material and is arranged on an outer peripheral side of the rotary atomizing head in a state where a front end of the shaping air spurting member is positioned in an intermediate section of the rotary atomizing head in a length direction, the front end being provided with many numbers of air spurting holes over an entire circumference of the shaping air spurting member in a circumferential direction to spurt shaping air toward paint particles sprayed from the rotary atomizing head (Patent Document 1).
In a case of performing the coating by using the electrostatic coating machine as configured above, the rotary atomizing head is rotated at high speeds by the air motor, and in this state, paint is supplied to the rotary atomizing head. Therefore, the paint supplied to the rotary atomizing head is atomized by centrifugal forces generated when the rotary atomizing head rotates and is sprayed as paint particles from the releasing edge. At this time, the shaping air spurting member sprays the shaping air spurted from each of the air spurting holes to the paint particles. As a result, the shaping air controls a kinetic vector component of the paint particle in a coating object direction to adjust a spray pattern of the paint particles to a desired shape.
Further, the external electrode member, by applying a negative high voltage to each of the electrodes, electrifies the paint particles sprayed from the releasing edge of the rotary atomizing head to be in the negative polarity. Thereby, the paint particles sprayed from the rotary atomizing head are indirectly electrified to be in the negative polarity. Accordingly, the electrostatic coating machine can fly the electrified paint particles along an electrostatic field formed between each of the electrodes and the coating object to cause the coating object to be coated with the paint particles.